Hi! My name is ***** ***** I'm happy to help!
You'll need to remove the profile from control panel.
A profile consists of accounts, data files, and settings that specify where your email messages are saved.
Open Control Panel by doing one of the following:
In Windows 8 and Windows 10, choose Start and type Control Panel.
In Windows Vista and Windows 7, choose Start > Control Panel.
Open Mail by doing one of the following:
In Windows 10, choose User Accounts > Mail.
In all other versions of Windows, choose Mail.
NOTE: The Mail icon appears after Outlook starts for the first time.
Choose Show Profiles.
Select a profile.
Respond here, and if I'm around I'll be glad to help, if not someone else will jump in. Thanks!
go to file / account settings / account settings
under the email tab
you will see your old email address that you no longer use ( along with the ones you do use)
select the one that you no longer use and get the message from
click the remove button
simple as that